Current measurements from electromagnetic current transformers are essential for the construction of secondary circuit systems, including for protection systems. Magnetic core of these transformers are at risk of saturation, as a result of which maloperation of protection algorithms can possibly occur. The paper considers methods for recovering a current signal in the saturation mode of current transformers. The advantages and disadvantages of methods for detecting the occurrence of current transformers core saturation are described. A comparative analysis of mathematical methods for recovering a current signal is given, their approbation was carried out, and the most promising of them was revealed. The stability and sensitivity of recovery methods were tested by adding white noise to the measured signal and taking into account the initial flux density (remanent magnetization) in the current transformers core. Their comparison is given on the basis of angular, magnitude, and total errors at a given simulation interval.

This paper proposes a structured hierarchical-multilevel approach to calculating the power flows and losses of electricity in radial electrical networks with different nominal voltages at given loads and voltages of the power source. The researched electrical networks are characterized by high dimensionality, dynamism of development, but also insufficient completeness and reliability of state information. The approach is based on the representation of the initial network graph in the form of a hierarchical-multilevel structure, divided into two stages with rated voltages $U_{nom}\le 35$ kV and $U_{nom}\ge 35$ kV, and using the traditional (manual) engineering two-stage method, where the calculation is performed in a sequence from bottom to top (stage 1) and from top to bottom (stage 2), moving along the structure of the network. The application of the above approach makes it possible to obtain an algorithm for implementation on a computer, which is characterized by universality (for an arbitrary configuration and complexity of the network), high performance and low requirements for the computer memory.

The present article is devoted to the issues of determining the static load characteristics by the passive experiment with the aim of improving the quality of control over the electric power system operation modes and reducing the amount of control actions from the emergency control devices. The problems of filtering a priori information identifying the dependencies of active and reactive power are considered, a technique for determining the regulating effect of the load and estimating the static load characteristics on the basis of a real power area are proposed. In addition, the problems of determining the error are considered, a solution realized on the basis of the principal component method that provides an increase in the accuracy of the passive experiment is proposed.

Up-to-date wide area measurement systems (WAMS) based on phasor measurement units (PMU) appeared at the very end of the 20th century....

In most of the world's energy systems, in recent years there has been a widespread introduction of synchronized phasor measurements (SPM). They allow both to obtain measurements of the traditional parameters of the established mode (voltage V and current I modules, active P and reactive Q power) with a time stamp, and to measure new parameters, namely, the phase angles of voltage δ and current φ. The focus on SPM in dispatching and emergency control systems is due to a number of factors, the most important of which is a sharp increase in the accuracy of measurements, since measurement non-synchronism is the main source of error in telemetry (TM).

In connection with the possibility of obtaining phasor measurements in the electrical power system, much attention is paid to the use of Phasor Measurement Unit (PMU) devices in the Wide Area Measurement System (WAMS), a large-scale distributed measurement system that provides complex vector telemetry of electrical parameters. The most important achievement in obtaining telemetry data with the help of the PMU is not only the high accuracy of power system state parameters measurements obtaining at various points in the bulk electrical system, such as, for example, the UES of Russia, but, as shown in previous authors' papers, in super-accelerated power flow calculations and state estimation of the electrical power system.